Rounding over numbers

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Hi all,

Is there a quick way to round off numbers as follows:

1.24 to 1.20
13.25 to 13.30
2.90 to 2.90
2.99 to 3.00
2.92 to 2.90
14 to 14.00
[download]

Thanks in anticipation :)